Terminal connections, like plug-in connections in general, are used for isolating and connecting electrical lines so as to transmit current and/or in particular electrical signals therethrough. These may be multiple or single plugs. Coaxial plug-in connections are of great importance in the field of plug-in connectors, which connections comprise an inner conductor, an outer conductor and generally an outer conductor shield, the inner conductor being electrically/galvanically isolated from the outer conductor generally using a dielectric.
In the process, it is desirable to be able to bring the coaxial cable into contact with the plug-in connector in as simple a manner as possible. This contact should be as reproducible as possible.
DE 693 07 329 T2 describes a terminal device for a cable. The terminal device comprises a connector which has a hollow region into which a solder deposit is introduced. Subsequently, an electrically conductive, resilient, sleeve-shaped compression coil is inserted. The inner conductor to be contacted of the cable to be received is inserted into this compression coil.
US 2010/0144200 A1 discloses a connector which can be used for terminating a coaxial cable. The connector comprises a holding apparatus against which a spring is supported by its first end. In addition, the spring in part abuts an inner wall of a receiving hole in the connector in the circumferential direction. The spring comprises a second end and tapers in diameter from the first end to the second end. The inner conductor of the coaxial cable to be received is introduced through the holding apparatus and held in a centred manner in the hole by the second end of the spring.
WO 2015/000749 discloses a terminal plug for a coaxial cable. The terminal plug comprises a holding element and a contacting element. The holding element consists of a dielectric and holds an inner conductor of the coaxial cable to be received in a centred manner in a receiving opening in the terminal plug. The contacting element contacts the inner conductor galvanically, and is additionally supported against the holding element. Protruding portions on the outer circumference of the contacting element, which engage in corresponding indentations in the holding element, prevent axial displacement of the contacting element with respect to the holding element.
DE 102 51 905 C5 discloses a plug-in connection consisting of a coaxial plug-in connector and a coaxial cable to be received. The plug-in connector comprises an outer conductor socket, which is used for contacting an outer conductor of the coaxial cable to be received. The plug-in connector also comprises an inner conductor receiving element, which has an inner conductor receiving hole. This inner conductor receiving element is used for receiving an inner conductor of the coaxial cable to be received. To establish electrical contact between the inner conductor of the coaxial cable to be received and the inner conductor receiving element of the plug-in connector, a solder deposit is arranged within the plug-in connector. The solder deposit may for example be arranged within the inner conductor receiving hole. However, the inner conductor receiving hole may also comprise a region having an expanded diameter, in which case the solder deposit is arranged within this region. After the exposed inner conductor of the coaxial cable is introduced into the plug-in connector, the solder deposit can be melted, for example using an induction loop, causing an electrically conductive connection to be established between the inner conductor of the coaxial cable and the inner conductor receiving element of the plug-in connector.
A drawback of DE 102 51 905 C5 is that different inner conductor receiving holes have to be provided for different diameters of the inner conductor to be received. In addition, a region having an expanded diameter is required in order to attach the solder deposit, and this requires an additional machining step. This makes the production process expensive.
The object of the present invention is therefore to provide a terminal connection by way of which a terminal apparatus can be connected to an HF inner conductor in as simple a manner as possible, even with different cables. The electrical contact between the HF inner conductor and the terminal apparatus should also be reproducible and as simple as possible to implement.
The object is achieved by the terminal connection described herein. This specification also describes an electronic device, in particular an HF filter, which comprises the terminal connection according to the invention. This specification additionally describes a method for producing a terminal connection of this type. Advantageous developments of the terminal connection or the electronic device or the method according to the invention for producing a terminal connection of this type can be found in the description.
The terminal connection according to the invention makes it possible to receive and contact an HF conductor with a terminal apparatus, for example in the form of a plug-in connector. The terminal apparatus comprises an HF conductor and an HF conductor receiving element comprising an HF conductor receiving hole for receiving the HF conductor. The terminal connection also provides the use of at least one solder deposit, which is used for establishing an electrically conductive connection between the HF conductor and the HF conductor receiving element of the terminal apparatus.
The terminal connection also provides an insertion sleeve, which has a receiving opening. The HF conductor is inserted into the receiving opening. The insertion sleeve is inserted into the HF-conductor receiving hole in the HF conductor receiving element via an insertion opening on the plug-in side. The at least one solder deposit is arranged in the insertion sleeve or on at least one of the two end faces of the insertion sleeve or on the HF conductor. The insertion sleeve is undeformable and/or consists of a dielectric. In addition or alternatively, the circumferential side face of the insertion sleeve is adapted to and supported against an inner face of the HF conductor receiving hole, and said sleeve is only displaceable in the longitudinal direction within the HF conductor receiving hole. In addition or alternatively, the insertion sleeve comprises at least one receiving channel, which extends inwards into the receiving opening, the at least one receiving channel being used for receiving the at least one solder deposit.
It is particularly advantageous to use an insertion sleeve which is inserted into the HF conductor receiving hole in the HF conductor receiving element. This insertion sleeve may comprise a solder deposit directly or a solder deposit may be arranged on the insertion sleeve, in other words adjacent thereto. When this solder deposit is melted, the HF conductor is thus connected to the HF conductor receiving element. On the one hand, the insertion sleeve causes the solder deposit to be arranged at a precisely stipulated location, resulting in precise and reproducible contacting of the HF conductor with the HF conductor receiving element. On the other hand, it is ensured that the same terminal apparatus can be used for different diameters of the HF conductor. It is merely necessary to use a different insertion sleeve having a different receiving opening adapted to the HF conductor to be received in each case. As a result, although the insertion sleeves have different diameters in terms of their receiving openings, they nevertheless have the same external diameter, meaning that a standard HF conductor receiving hole can be used. In addition, it is always possible to use fresh solder since it is not arranged within the HF conductor receiving hole, where it would age until the soldering process. The terminal apparatus itself can therefore be stored for as long as is desired, and is only provided with an insertion sleeve, which preferably has a fresh or unaged solder deposit, during the process of being joined to the HF conductor.
In the context of the invention, it is therefore apparent that the terminal apparatus is equally suitable for receiving inner conductors of different diameters.
In another independent claim, an electronic device, which is in particular an HF filter, comprises the terminal apparatus according to the invention. The HF conductor receiving hole, into which the insertion sleeve is introduced together with the solder deposit, is for example formed in a resonator inner conductor of the HF filter. Finally, the HF conductor is inserted into the insertion sleeve and soldered to the HF conductor receiving element.
A further advantage is provided if the insertion sleeve is undeformable, in other words non-resilient, since this causes the distance between the HF conductor and the HF conductor receiving element to be constant and ensures high reproducibility of the soldering point. In this context, the insertion sleeve consists of a dielectric, in particular a plastics material. A plastics material has a low heat capacity, meaning that less energy is required during inductive heating of the solder deposit or that the melting process can take place in a shorter time than if the insertion sleeve were made of a metal, this being another possibility. In addition, the circumferential side face of the insertion sleeve is adapted to the inner face of the HF conductor receiving hole, specifically both in diameter and in shape, and said sleeve is therefore supported against it and is only displaceable in the longitudinal direction within the HF conductor receiving hole. The insertion sleeve and the HF conductor receiving element, which comprises the HF conductor receiving hole, are two separate elements. This means that the insertion sleeve and the HF conductor receiving element are formed as two parts. The HF conductor receiving hole is left unchanged by the attachment of the insertion sleeve.
A further advantage is provided if the solder deposit consists of a rigid or resilient material and is preferably in the form of a partially open or closed ring, or if the solder deposit is viscous. In particular the use of a solder deposit that consists of a rigid or resilient material in the form of an open or closed ring means that this solder deposit can be placed on the HF conductor in a very simple manner.
The insertion sleeve preferably also comprises at least one coding element on the circumference thereof, meaning that the insertion sleeve can only be inserted into the HF conductor receiving element in a particular position in a twist-proof manner. The insertion sleeve may optionally or additionally also comprise, on the circumference thereof, at least one portion which projects into the HF conductor receiving element counter to the insertion direction and acts as a barb, preventing the insertion sleeve from sliding out of the HF conductor receiving element. This means that the solder deposit is always inserted into the terminal apparatus together with the insertion sleeve in the same position. The coding element may also be provided by way of the shape of the insertion sleeve. If the insertion sleeve has an oval or n-gon cross section, n being ≧3, instead of a round cross section, this is already sufficient to prevent rotation. However, the HF conductor receiving hole then has to be produced by a different process. This further increases the reproducibility of the electrical contacting. The fact that the insertion sleeve comprises a type of barb additionally results in simplified assembly, since the insertion sleeve can no longer slide out of the HF conductor receiving hole.
The insertion sleeve is preferably arranged in a manner limited by a stop within the HF conductor receiving element, in such a way that the reproducibility of the electrical contacting is also increased, because the distance between the at least one solder deposit and the HF conductor receiving element is the same for a large number of terminal apparatuses.
The receiving channel is in particular in the form of a hole. The receiving channel preferably extends radially inwards from the outside into the receiving opening, the at least one receiving channel being used for receiving the at least one solder deposit. In this context, it is particularly advantageous that the insertion sleeve can be prepared appropriately together with the solder deposit until the terminal apparatus is finally joined to the HF conductor.
It is also possible for the insertion sleeve to have X receiving channels, X being ≧2, these receiving channels being arranged so as to be spaced apart by α=360°/X in a plan view of a cross section through the insertion sleeve. This means that the HF conductor is electrically contacted with the HF conductor receiving element symmetrically, increasing the reproducibility of the electrical connection.
It is also possible for the receiving channel to be in the form of a cut-out that covers a range of more than 180°, preferably more than 220°, more preferably more than 260°, more preferably more than 300°, more preferably more than 340°, but less than 360° in a plan view of a cross section through the insertion sleeve. A solder deposit which is in the form of an open ring and consists of a rigid or partially resilient material can be arranged within this cut-out in a particularly simple manner. This solder deposit can be “clipped” into the receiving channel in the form of a cut-out in a simple manner.
In addition, the HF conductor is enclosed over at least part of the length thereof by a rigid dielectric, which is enclosed over at least part of its length by an outer conductor, in such a way that the HF conductor forms the inner conductor of a coaxial cable which is to be or has been received. In this case, the terminal apparatus is a plug-in connector. The plug-in connector comprises an outer conductor socket for receiving the coaxial cable. The outer conductor socket comprises an outer conductor contacting portion, on which the outer conductor of the coaxial cable which is to be or has been received is electrically contacted with the outer conductor socket of the terminal apparatus. In this case, the terminal connection comprises at least one adapter element. The at least one adapter element is arranged between the outer conductor contacting portion and the HF conductor receiving element, and encloses the HF conductor, preferably radially, either alone or together with the dielectric of the coaxial cable which is to be or has been received. As a result, the surge impedance of the coaxial cable can be adjusted to a desired value.
The method according to the invention for producing a terminal connection comprises the following method steps. In a first method step, the HF conductor to be received has to be prepared. This can be done by:                a) placing a solder deposit on the HF conductor and further placing the insertion sleeve on the HF conductor, either in succession or simultaneously; or        b) placing the insertion sleeve and a solder deposit on the HF conductor, either in succession or simultaneously; or        c) placing the insertion sleeve on the HF conductor, the at least one solder deposit already being arranged in the insertion sleeve; or        d) placing the insertion sleeve on the HF conductor and attaching the at least one solder deposit in the insertion sleeve.        
Subsequently, the HF conductor is inserted into the HF conductor receiving element of the terminal apparatus, together with the insertion sleeve and the at least one solder deposit.
Instead of the first method step, the terminal apparatus may be appropriately prepared in a second method step. This is done by:                a) arranging the at least one solder deposit in the insertion sleeve and inserting the insertion sleeve into the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus together with the at least one solder deposit; or        b) inserting the insertion sleeve into the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus and inserting or introducing a solder deposit into the space, remaining towards the insertion opening, in the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus; or        c) inserting a solder deposit into the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus, and further inserting or introducing the insertion sleeve into the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus.        
Subsequently, the HF conductor is inserted into the receiving opening in the insertion sleeve or into the receiving opening in the insertion sleeve and the annular solder deposit.
Instead of the first method step or the second method step, both the coaxial cable and the terminal apparatus may be appropriately prepared in a third method step. This is done by:                a) inserting the insertion sleeve into the HF conductor receiving hole in the HF conductor receiving element of the terminal apparatus and placing a solder deposit on the HF conductor, either in succession or simultaneously.        
Subsequently, the HF conductor is inserted into the receiving opening in the insertion sleeve.
In a fourth method step, the solder deposit is heated until it is melted into a liquid. Electrical contact between the HF conductor and the HF conductor receiving element is thus established. It is particularly advantageous that on the one hand the insertion sleeve can be slipped over the HF conductor or on the other hand the insertion sleeve can be inserted into the HF conductor receiving hole in the HF conductor receiving element. This makes it possible either for the HF conductor to be prepared as a separate element together with the insertion sleeve and the solder deposit, or for the terminal apparatus to be prepared together with the insertion sleeve and optionally the solder deposit.